1. to become romantically linked with someone and see them on a regular basis.
2. to leave you usual hiding place and emerge from under the stone. THis could be a trip to the local store for some milk, to go and retrive someone's guinea pig or a night out involving alcohol. If the person is normal, when they leave the house they will not want to see anyone they know. Being Insociable is good.

1. 'oh, I'm going out with Chris'
2. 'I'm just going to go out and get some cheese so i can melt it on my toast. Be back soon.'

1) For a middle school student usually means walking to classes together, giving hugs, dancing to slow songs at dances, possibly going on "group date" on weekends, and communicating regularly.
2) For a high school student usually means doing that above^ and usually more one-on-one dating on a regular basis.

1) "Scott and Beth broke up after four months of going out."
2) "I saw Jane and Mark at the movie theater togther. Are they going out?"

1)are bob and sally going out?
2)yes
1)are joe and anna going out?
2)yes
1)are tim and julie going out?
2)no, they broke up now tim is going out with becky.
1)did any of them actually go on a date?
2)well, no not yet

In college, used as a verb (mostly between freshmen) to describe the act of pursuing a college party in the hopes of getting drunk. Most of the time this is done without any knowledge of where a party actually is, and asking random drunk people on the street where alcohol can be found.

"Hey, you guys going out tonight?"
"Oh yeah, we're gonna get wasted!"
"Walk around campus for an hour to find a dead party and say we got drunk? Count me in!"